Abstract

Colloidal phenomena in porous media, natural or engineered, are important in a breadth of science and technology applications, but fundamental understanding is hampered by the difficulty in measuringcolloid deposit morphology in situ. To partially address this need, this paper describes a static light scattering apparatus using a flow cell filled with refractive index matched (RIM) porous media, allowing real-time measurement of colloidal phenomena as a function of depth within the flow cell. A laser interacts with the colloids in the pore space and their structures, but not with the RIM media. The intensity of scattered light is measured as a function of scattering angle, which allows characterization of colloid deposit morphology as a fractal dimension and a radius of gyration. In parallel, fluid discharge rate and pressure drop are recorded to determine permeability, a key parameter for any application involving flow through porous media. This apparatus should prove useful in any application requiring characterization of colloidal phenomena within porous media. Additionally, this paper describes how to use granular Nafion as RIM porous media.

The authors thank Katerina Kechris for guidance on the bootstrap and two anonymous referees whose comments helped to clarify the presentation. This research was supported by the U.S. Department of Energy, Subsurface Biogeochemistry Research Program (Award No. DE-SC0006962). B.G. was supported as part of the Subsurface Science Scientific Focus Area funded by the U.S. Department of Energy, Office of Science, Office of Biological and Environmental Research (Award No. DE-AC02-05CH11231).

Key Topics

[Colloid chemistry, e.g. the production of
colloidal materials or their solutions, not otherwise provided for; Making
microcapsules or microballoons, Colloid chemistry, e.g. the production of colloidal materials or their solutions, not otherwise provided for; Making microcapsules or microballoons]